ASA 130th Meeting - St. Louis, MO - 1995 Nov 27 .. Dec 01

3aPP4. Diufhuis pitch and other anomaly pitches.

Jian-Yu Lin

William Morris Hartmann

Dept. of Phys., Michigan State Univ., East Lansing, MI 48824

``Anomaly pitches'' are tonal sensations caused by anomalies in the
spectrum of a low-frequency periodic wave, for example, by a missing harmonic
[Duifhuis, J. Acoust. Soc. Am. 48, 888 (1970)]. They are immediately heard in
the steady state and do not require any reference signal. This paper reports
anomaly pitches for both missing harmonics and inverted harmonics. They occur in
pulse waves (for any constant phase), in sawtooth waves, in waves with
alternating sine and cosine phases, and in waves with Schroeder phase. With a
series of missing upper harmonics it is possible to make a virtual anomaly pitch
with a missing fundamental. The observations can be compared with the original
explanation of the effect by Duifhuis based upon detection of the anomalous
harmonic during gaps. Some of the conditions press this explanation to the limit
but none has proved fatal. [Research supported by the NIDCD of the NIH.]